I know there is a prior thread on this, but its closed.
I noticed that you said that you could create a migrator for desk (or perhaps just do some custom work for us, to migrate our cases.) We would be happy to share our api keys so you could poke around with our desk ticket system, but its pretty simple.
FYI our shop is 100% ruby on rails, so we can certainly help with the migration, I am just limited on how many developers I would put on this issue.
Realizing this is probably more appropriate as a private email thread here is my email firstname.lastname@example.org. Feel free to close or delete this issue if appropriate.